Grinding-tongs for spiral drills.



No. 891,738. PATENTED JUNE 23, 1908.

O. SGHUBE.

GRINDING TONGS FOR SPIRAL DRILLS.

APPLIQATION IILBD SEPT. 28. 1906.

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. aws are guided one by the other, the jaw b I OTTO SOHOBE, OF HALLE-ON-THE-SAALE, GERMANY.

GRINDING-TONGS FOR SPIRAL DRILLS.

Specification of Letters Patent. Application filedZSeptember 28, 1906.

understood that the operator grasps the levers or handles 0 and thus exerts the required degree of pressure for holding the drill firmly between the jaws a and b. Associated with these gripping jaws is the grinding pattern 9. This is held in proper posij tion by means of arms e and f which are mov- I ably secured to the said jaws so as to allow movement of the latter in opening and closing. This pattern plate has a profile corre sponding to that required for the grinding true of the spiral drill on both sides. In the known, it has been difficult to grind the cutuse of the appliance the drill h is held by the ting faces uniformly, and it frequently hap- I jaws of the tongs with the drill having its pens that the drill is torn from the operators 1 cutting edge fitted into the pattern as inclihand while being ground and the cutting j cated in Figs. 1 and 4, and by this means the face which has already been ground is thus grinding is performed while the drill is held destroyed. securely in place and in connection with the The present pattern. for positively gripping the spiral drills and I claim as my invention: pattern means having a profile correspond- 1. An appliance for holding spiral drills ing to the shape which the spiral drill must I while being ground comprising a pair of tongs have when ground. having jaws which have a tongue and groove The invention consists in the features and connection between them, said jaws being combination and arrangement of parts hereadapted to grip the drill and a pattern plate inafter described and particularly pointed corresponding in profile to the drill to be out in the claims. ground, and two movable arms for holding In the accompanying drawings,Figurel the plate i position, substantially as deis a front view of the invention, 2 is a scribed. I side view looking from the right of Fig. 1. 2. An appliance for holding spiral drills Fig. 3 is a rear view, and Fig. 4 is a side view comprising the tongs for gripping the drills, looking from the left of Fig. 1. the pattern member and the movable arms The appliance is in the form of a pair of connecting the pattern member to the jaws tongs, the lever arms of which are indicated of the tongs. at 0. These arepivoted together at c and In testimony whereof I have signed my they have opposing jaws a and I). These name to this specification in the presence of two subscribing witnesses.

OTTO SOHOBE.

No. 891,738. Patented June 23, 1908.

Serial No. 336,644.

T 0 all whom it may concern:

Be it known that I, OTTO SoHoBE, subject of Emperor of Germany, residing at N o. 13 Zinksgartenstrasse, Halleon-the-Saale, Germany, haveinvented new and useful Iniprovements in Grinding-Tongs for Spiral j Drills, of which the following is a specification.

It is the object of my invention to provide means for holding the spiral drills while being ground or sharpened. In grinding spiral j drills as heretofore practiced, as is well invention comprises means having a tongue 6 to enter a slot or groove a in the jaw a. Each jaw has a recess d adapted in shape for securely holding the drill during the grinding operation, it being Witnesses HUeo Mr'iLLER, KARL KLEMM. 

